Ladder



(No Model.)

P. s. SEAGRAVB.v

LADDER.

No. 8473848.r Patented Aug. 17, 1888.

- IJVVLWTOR MIJ WITNESSES cwgaedm/ W7 f 8 4 Attorney as more fullyhereinaf'ter described.

VUNITED STATES PATENT OFFICE.

FREDERIC S. SEAGRAVE, OF BAY CITY, MICHIGAN.

LADDER.

SPECIFICATION forming part of Letters Patent No. 347,648, dated August17, 1886.

Application filed March Q5, 1886.

.To all whom it may concern:

Beit known that l, FREDERIC S. SEAGRAVE, of Bay City, in the county ofBay and State of Michigan, have invented new and useful Improvements inLadders; and I do hereby declare that the following is a full, clear,and exact description thereof, reference being had to the accompanyingdrawings, which form a part lof this specification.

The nature of this invention relates to certain new and usefulimprovements in the construction of laterally-braced and trussed ladders, by means of which a very effective, long, and efficient ladder ismade, which will support a very heavy weight and be entirely free underall stresses from lateral swaying, while the parts are so arranged asnot to interfere with the operations of the person who may be using theladder.

The invention consists in the peculiar construction, combination, andoperation of parts,

Figure 1 is a front elevation with the ladder in an inclined position.Fig. 2 is a side elevation. Fig. 3 is a cross-section on the line x inFig. l.

In the accompanying drawings, which form a part of this specification, AA represent two legs of a ladder, which are constructed in the usualway, except as hereinafter mentioned, and theyv are secured together bythe rounds B, in the usual manner.

C C are trusses, preferably made of thin pieces ot' wood, one beingprovided for each leg, and secured thereto by means of bolts a, andvhybeing halved with the leg, or, preferably, by inserting a dowel-piubetween the truss and the leg, either by driving said dowel to force itsown way, or into a hole or mortise prepared for the same,to provideextra resistance against end pressure or tension, which might destroythe efficiency ofthe trusses provided the bolts were simply relied uponto hold the trusses in place.. I

The rounds in my improved ladder are practically of the samelength fromthe top of the ladder to a point near its center, so that the sides ofthe upper end of the ladder will be practically parallel, while fromnear such central part the rounds increase in 'length toward the bottom,thereby spreading the sides and giving abroader base to the ladder. Thetruss' Serial No. 196,457. (No model.)

forms almost a direct line (looking at the device from the front) fromthe top to the hottom of each leg; or it may be slightly deflectedoutwardly at the center, as shown in Fig. l, and forced backward at thecenter by the struts D, E, I, and G, the latter of which is arched orcurved, the ends thereof being secured to any circumstances inlongladders, while shorter ones may be found sulciently strong with thetrusses directly in rear of the leg, the parts being connected togethersubstantially as described. It will readily be seen that, by thisconstruction andarrangement of parts, very little timber is required anda maximum of strength is obtained in a very light ladder.

Vhat I claim as my invention isl. A ladder having an expanded base, thespread of which increases downwardly from the center, and provided wit-hindependent wooden trusses secured to the ends of each leg, and strutsbetween said legs and trusses, substantiall y as described.

2. A ladder provided with wooden trusses curved rearwardly andoutwardly,and secured to the legs of the ladder by means of bolts orrivets, and supported against end-strain by halving 7 the said trussesin theladderiegs, or by dowel-pins, substantially as and for the purposedescribed.

3. In combination with a ladder provided with trusses secured theretointhe manner de-` scribed, the struts, by means of which such trussesare secured in position, such struts be,- ing of varying lengths andextending beyond the two sides of the ladder proper, substantially asshown. t

4. In combination with a trussed ladder, constructed substantially asdescribed, the central arched struts, substantially as and for thepurposes set forth.

FREDERIC S. SEAGRAVE.

Vitnesses:

D. C. WILLIAMSON, FREDK. P. BRowNE.

